Musical instrument construction



United States Patent O MUSICAL INSTRUMENT CONSTRUCTION Russell B. Bedford III, 8000 E. Avon Lane, Lincoln, Nebr. 68505 Filed Apr. 20, 1967, Ser. No. 632,282

Int. Cl. G10d 7/00 U.S. Cl. 84-380 9 Claims ABSTRACT F THE DISCLOSURE A key mounting means for a musical instrument in which a low lfriction, wear resistant plastic member is This invention relates to ymusical instruments, and more particularly to key mounting means for a woodwind type instrument.

In the design and manufacture of musical instruments of the woodwind type, wherein a series of tone holes are arranged along the length of the instrument, it is necessary to provide pads, or the like, for opening and closing such tone holes in order to produce the musical sound desired. Since the tone holes are variously spaced along the length of the instrument, it is'necessary to provide a key operating structure connected to each of the pads, with the keys so located as to be actuated from convenient locations for easy and rapid finger movements. To this end, the pads are generally mounted on a key shaft or hinge rod, supported by posts from the body of the instrument, and rotatable into and out of engagement with the tone hole by a key located at a point remote from the pad.

There are two basic types of key hinge assemblies normally used in the design and manufacture of musical instruments. The rst of these is a pivot screw which is threadedly received in a post and extends through the post to support a key shaft. On one of the key shafts, a finger actuated key is mounted and near the other end of the shaft the pad is mounted. This kind of structure requires drilling and tapping operations in the post to receive the pivot screw, and suitable drilling and reaming operations in the end of the key shaft to receive the pivot screw. The key shaft normally rotates about the extension of the screw upon actuation of the key.

A second type of basic mounting assembly includes a pivot rod which extends between a pair of spaced posts, and a key shaft is concentrically mounted on the pivot rod for rotation about the surface of the pivot rod. Such pivot rods are also threadedly received in the posts and must be manufactured and assembled with great precision.

Each of the basic types of mounting assemblies above described are subject to very rapid wear. The parts are normally metallic parts, the rotating key shaft being usually constructed of a softer metal than the pivot screw or pivot rod, and rapid wear leads to expensive and time consuming replacement and repair operation. To combat the wear problem, it is the usual practice to provide lubrication between the relatively rotating parts. However, such lubrication further adds to the problems by picking up dirt and `foreign particles, also contributing to the rapid wear. Further, the pivot screw and/ or pivot rod are subf. ICC

ject to moisture and salts from the hands and quickly corrode.

One of the basic results of the wear problems in the normal key assembly mounting is the noise of the mechanism once wear has started. There is a continuous clanking or clatter when the keys are depressed and released, the noise becoming louder with each playing of the instrument as the war progresses and the fit loosens.

The device in which this invention is embodied comprises, generally, a key mounting assembly in which a low friction and low wear plastic material is disposed between the rotating key shaft and its post mounting in order to provide lubricity and diminish the wear problem. In one embodiment of the invention, the pivot shaft itself is formed of such low friction plastic material, and further low friction plastic material is provided between the post and the key shaft to both increase the life of the assembly and to eliminate much of the noise resulting from improper adjustment or slight wear between the parts. In other embodiment of the invention, where the key shaft is concentric to and supported on a pivot rod, the shaft is supported by means of low friction plastic material having lubricity properties and low wear characteristics.

In any embodiment of the invention, the pivot member may be held in place within the post in such a way as to eliminate the costly and time consuming drilling and tapping operations, and to permit easy replacement of existing key mounting assemblies where the wear problem has already occurred, thus eliminating the usual expense, time consumption and degree of precision normally necessary in repair.

These and other advantages will become more apparent from the following description and drawing in which:

FIGURE 1 is a plan view of a portion of a musical instrument showing the mounting of a key, key shaft and pad thereon.

FIGURE 2 is an enlarged view, with parts broken away and in section, of a portion of the assembly illustrated in FIGURE 1, taken substantially along the line 2-2 of FIGURE 1 and looking in the direction of the arrows.

FIGURE 3 is a view similar to FIGURE 2, with parts broken away and in section, illustrating a modification of the structure shown in FIGURES l and 2.

FIGURE 4 is a cross sectional view of the structure illustrated in FIGURE 3, taken substantially alone the line 4-4 of FIGURE 3 and looking in the direction o the arrows.

FIGURE 5 is a view similar to FIGURE 2, with parts broken away and in section, showing another modification of the assembly.

FIGURE 6 is a view similar to FIGURE 2, with parts broken away and in section, illustrating yet another modification of the mounting assembly.

Referring more particularly to the drawing, FIGURE 1 best illustrates the overall structure in which a woodwind instrument, indicated generally by the numeral 10, is provided with a tone hole or cylinder 12, one of many along the length of the instrument. Tone hole 12 is selectively covered or uncovered lby a pad 14, secured to a lever 16 which in turn is secured to and extend from a rotating key shaft, indicated generally by the numeral 18.

instrument by a leg 26 and having an opening 28 formed in any suitable manner therethrough. The portion of the head 24 adjacent the end of the key shaft 18 is formed with an enlarged cylindrical recess 30` which is coaxial with the opening 28. Received in opening 28 and extending through the head 24 of the post 22 is a pivot member, indicated generally by the numeral 32. Pivot member 32 includes an enlarged head 34 and extending therefrom is a shank portion 36 received in the opening 28 in the po-st head 24. Extending beyond the post 22 is a conical pivot section 38, received in a conical recess 40 formed in the end of the key shaft 18. Thus, the key shaft 18 is allowed `to rotate about the conical portion 38 in the actuation of the pad 14 by the key 20.

Intermediate the ends of the shank portion 36 of the pivot member 32 is an annular groove 42, formed therein in any suitable manner. Disposed within the recess 30 in the post head 24 is a member of low friction plastic material, indicated generally by the numeral 44, the member having an internal annular flange 46 which is receivable in the annular groove 42 in the pivotmember 32. When properly positioned, the pivot member 32 is thus held in place in the post member 22 by clamping between the annular flange 46 in the groove 42 and the inner surface of the enlarged head 34.

Member 44is formed of any suitable low friction plastic material which has lubricity and low wear characteristics. Typical of such material is Teflon. Pivot member 32 may also be formed of such material to decrease Wear and noise in the rotation of key shaft 18 about the conical end portion 38 of the pivot member. The outward face of member 44 may extend slightly outwardly of the head 24 of the post 22 to assure contact with the adjacent face of the key shaft 18, and thus properly position the various parts of the overall assembly. At the same time, low friction and wear resistance are present to increase the life of the assembly.

Referring to FIGURES 3 and 4, another preferred embodiment of the invention is illustrated, in which the key shaft 18 is pivotally mounted on a pivot member 32 having an enlarged head portion 34', a shank 36 and a conical end portion 38. Key shaft 18 is provided with a conical recess `40 to receive the conical end portion 38' of the pivot member 32'. Pivot member 32' passes through an opening 28', formed in the post 22 as hereinbefore described, and a low friction member 44 is received in a recess 30 formed coaxially with the opening 28'.

Pivot member 32 is provided with an annular groove 42 within the post 22, such groove being aligned with a transverse slot 48 formed in any suitable manner through the post 22. Received in slot 48 and in the annular groove 42 is a retainer member S0, having a radial opening 52 permitting the retainer member to be snapped over the pivot member 32 and thus locking the pivot member in the post 22'.

The pivot member 32 and the member 44 may be formed of low friction plastic material, such as Teflon as hereinbefore described, so that the relatively moving parts are subjected to lubricity and low wear characteristics. Thus the member 44 has an outside surface that either extends slightly beyond the post 22', or is of a diameter at least as great as the outside diameter of the key shaft 18, thus assuring contact of the adjacent face of the key shaft 18vwith the low friction plastic material.

In FIGURE 5, yet anotherV preferred embodiment of the invention is shown wherein a key shaft, indicated generally by the numeral 54, is mounted for rotation on a pivot rod 56 extending between spaced posts, only one of which is shown at 58. Post 58 includes an enlarged head portion y60 supported from the body of the instrument 10 by a leg 62, and has an opening `64 formed at least partially therethrough. Coaxial with the opening 64 is a recess v66 in which is received a member of low friction plastic material, indicated generally by the numeral `68, for purposes to become hereinafter more apparent. Pivot-rod 56 extends into, or through, the head 60 of the post 58, and in the portion within the head 58 is formed an annular groove 70 to receive an annular -ilange 72 formed in the interior of the member 68. With such a mounting, the pivot rod 56 is securely held between the spaced posts 58 by the member 68 and the counterpart thereof in the other post, the annular flanges 72 being snappedinto the annular grooves 70 upon assembly. The member 68 has an outward face which either extends slightly beyond the post 58 and/or is of a diameter at least as great as the key shaft 54, to assure contact of the adjacent face of the key shaft 54 with the low friction plastic material.

Referring next to FIGURE 6, still another preferred embodiment of the invention is illustrated, in which the key shaft 74 is mounted between spaced posts,76, only one of which is shown, and is coaxial with a pivot rod 78. Post 76 has an internal opening 80 formed -therethrough to receive the pivot rod 78, rod 78 having an annular groove 82 formed in the portion thereof within the post 76. Aligned with the groove 82 is a transverse slot 84, formed in the post 76 in any suitable manner, slot 84 receiving a retainer member 86 in a maner similar to that hereinbefore described with reference to FIGURES 3 and 4, and which snaps into place in the groove 82 to lock the pivot rod 78 in the post 76.

Disposed between the pivot rod 78 and the key shaft 74 is a sleeve member 88, suitably received in the key shaft 74 and rotatable about the pivot rod 78. Sleeve member 88 is formed of a low friction plastic material and terminates in an enlarged outwardly directed flange 90, disposed between the end of the key shaftand the adjacent surface of the post 76, thus providing the low friction and low wear properties desired between the moving parts.

Thus, a `key pivot assembly iS provided for a musical instrument that eliminates the rapid wear normal-ly found in presently available constructions. By disposing low friction, wear resistant plastic materials at both the pivot surfaces and the end surfaces of the key shaft, the parts are readily insulated from wear and noise, contributing to a longer life and less expensive maintenance of the instrument. The assembly is such that hinge assemblies in present musical instruments may be easily replaced to eliminate future wear and life problems.

I claim:

1. A hinge assembly for a key of a musical instrument comprising:

a post secured in the body of said instrument tending outwardly therefrom;

a -key shaft rotatably mounted on said post;

a pivot 4member extending through said post and pivotally supporting said -key shaft, said pivot member having an annular groove formed therein;

and means coacting with said annular .groove lin said pivot member for preventing axial movement of said pivot member relative to said post, said meansincludng low friction means disposed between adjacent faces of said key shaft and said post.

2. The hinge assembly set forth in claim` 1 wherein said means coacting with said groove in said pivot member includes an inwardly directed annular flange extending into said annular groove in said pivot member.

3. The hinge assembly set forth in claim 2 wherein said pivot member has an enlarged rhead at one end thereof and a conical portion at the other end thereof received in said key shaft, and said pivot member being of a low friction .plastic material.

4. The hinge assembly set forth in claim 2 wherein said post has a cylindrical recess in the face thereof adjacent said key shaft, and said means coacting with said and exan-nular groove is received in said recess.

said means coacting with said groove in said pivot member includes an inwardly directed annular ilange onsaid annular member and extending into said groove in said pivot member.

7. A hinge assembly for a key of a musical instrument comprising:

a post secured in the body of said instrument and extending outwardly therefrom;

a key shaft rotatably mounted on said post;

a pivot member extending through said post and pivotally supporting said key shaft, said pivot member having an annular groove formed in the portion thereof within said post;

a transverse slot in said post and a retainer member received in said slot and coacting with said annular groove in said pivot member for preventing axial movement of said pivot member relative to said post;

and second means of low friction material disposed between adjacent faces of said key shaft and said post.

8. The hinge assembly set forth in claim 7 wherein said second means includes a sleeve portion received in said key shaft and on said pivot member, said sleeve portion having an annular flange extending outwardly therefrom and between said key shaft and said post.

9. The hinge assembly set forth in claim 7 wherein said post has a cylindrical recess formed in the face thereof adjacent said key shaft, and said second means is received in said recess in said post.

References Cited UNITED STATES PATENTS STEPHEN J. TOMSKY, Primary Examiner L. R. FRANKLIN, Assistant Examiner U.s. C1. X.R. slr-382, 385; ras-8.8 

